NCERT Class 11 Physics very short Questions & Answers
31 The material suitable for making electromagnets should have
Answer: high retentivity and low coercivity.
32 Curie temperature is the temperature above which
Answer: a ferromagnetic material becomes paramagnetic.
33 Three needles N1 N2 and N3 are made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively. A magnet, when brought close to them, will
Answer: attract N1 strongly, N2 weakly and repel N3 weakly.
34 Which of the following options are correct? If a conductor has a potential V 4- 0 and there are no charges anywhere else outside, then
Answer: there cannot be any charge in the body of the conductor.
35 Which of the following options is correct? In a region of constant potential
Answer: the electric field is zero.
36 64 drops each having the capacity C and potential V are combined to form a big drop. If the charge on the small drop is q, then the charge on the big drop will be
37 The radii of two metallic spheres A and B are r1 and r2 respectively (r1 > r2). They are connected by a thin wire and the system is given a certain charge. The charge will be greater
Answer: on the surface of the sphere A.
38 A magnetic needle is kept in a non-uniform magnetic field. It experiences
Answer: a force and a torque.
39 Let the magnetic field on earth be modelled by that of a point magnetic dipole at the centre of earth. The angle of dip at a point on the geographical equator
Answer: can be zero at specific points.
40 A strong magnetic field is applied on a stationary electron. Then the electron
Answer: remained stationary.